include/vlc_codec.h

   1 /*****************************************************************************
   2  * vlc_codec.h: Definition of the decoder and encoder structures
   3  *****************************************************************************
   4  * Copyright (C) 1999-2003 VLC authors and VideoLAN
   5  * $Id$
   6  *
   7  * Authors: Gildas Bazin <gbazin@netcourrier.com>
   8  *
   9  * This program is free software; you can redistribute it and/or modify it
  10  * under the terms of the GNU Lesser General Public License as published by
  11  * the Free Software Foundation; either version 2.1 of the License, or
  12  * (at your option) any later version.
  13  *
  14  * This program is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  17  * GNU Lesser General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU Lesser General Public License
  20  * along with this program; if not, write to the Free Software Foundation,
  21  * Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
  22  *****************************************************************************/
  23
  24 #ifndef VLC_CODEC_H
  25 #define VLC_CODEC_H 1
  26
  27 #include <assert.h>
  28
  29 #include <vlc_block.h>
  30 #include <vlc_es.h>
  31 #include <vlc_picture.h>
  32 #include <vlc_subpicture.h>
  33
  34 /**
  35  * \defgroup codec Codec
  36  * Decoders and encoders
  37  * @{
  38  * \file
  39  * Decoder and encoder modules interface
  40  *
  41  * \defgroup decoder Decoder
  42  * Audio, video and text decoders
  43  * @{
  44  */
  45
  46 typedef struct decoder_owner_sys_t decoder_owner_sys_t;
  47
  48 /*
  49  * BIG FAT WARNING : the code relies in the first 4 members of filter_t
  50  * and decoder_t to be the same, so if you have anything to add, do it
  51  * at the end of the structure.
  52  */
  53 struct decoder_t
  54 {
  55     VLC_COMMON_MEMBERS
  56
  57     /* Module properties */
  58     module_t *          p_module;
  59     decoder_sys_t *     p_sys;
  60
  61     /* Input format ie from demuxer (XXX: a lot of field could be invalid) */
  62     es_format_t         fmt_in;
  63
  64     /* Output format of decoder/packetizer */
  65     es_format_t         fmt_out;
  66
  67     /* Tell the decoder if it is allowed to drop frames */
  68     bool                b_frame_drop_allowed;
  69
  70 #   define VLCDEC_SUCCESS   VLC_SUCCESS
  71 #   define VLCDEC_ECRITICAL VLC_EGENERIC
  72 #   define VLCDEC_RELOAD    (-100)
  73     /* This function is called to decode one packetized block.
  74      *
  75      * The module implementation will own the input block (p_block) and should
  76      * process and release it. Depending of the decoder type, the module should
  77      * send output frames/blocks via decoder_QueueVideo(), decoder_QueueAudio()
  78      * or decoder_QueueSub().
  79      *
  80      * If p_block is NULL, the decoder asks the module to drain itself. The
  81      * module should return all available output frames/block via the queue
  82      * functions.
  83      *
  84      * Return values can be:
  85      *  VLCDEC_SUCCESS: pf_decode will be called again
  86      *  VLCDEC_ECRITICAL: in case of critical error, pf_decode won't be called
  87      *  again.
  88      *  VLCDEC_RELOAD: Request that the decoder should be reloaded. The current
  89      *  module will be unloaded. Reloading a module may cause a loss of frames.
  90      *  When returning this status, the implementation shouldn't release or
  91      *  modify the p_block in argument (The same p_block will be feed to the
  92      *  next decoder module).
  93      */
  94     int                 ( * pf_decode )   ( decoder_t *, block_t *p_block );
  95
  96     /* This function is called in a loop with the same pp_block argument until
  97      * it returns NULL. This allows a module implementation to return more than
  98      * one output blocks for one input block.
  99      *
 100      * pp_block or *pp_block can be NULL.
 101      *
 102      * If pp_block and *pp_block are not NULL, the module implementation will
 103      * own the input block (*pp_block) and should process and release it. The
 104      * module can also process a part of the block. In that case, it should
 105      * modify (*pp_block)->p_buffer/i_buffer accordingly and return a valid
 106      * output block. The module can also set *pp_block to NULL when the input
 107      * block is consumed.
 108      *
 109      * If pp_block is not NULL but *pp_block is NULL, a previous call of the pf
 110      * function has set the *pp_block to NULL. Here, the module can return new
 111      * output block for the same, already processed, input block (the
 112      * pf_packetize function will be called as long as the module return an
 113      * output block).
 114      *
 115      * When the pf function returns NULL, the next call to this function will
 116      * have a new a valid pp_block (if the packetizer is not drained).
 117      *
 118      * If pp_block is NULL, the packetizer asks the module to drain itself. In
 119      * that case, the module has to return all output frames available (the
 120      * pf_packetize function will be called as long as the module return an
 121      * output block).
 122      */
 123     block_t *           ( * pf_packetize )( decoder_t *, block_t **pp_block );
 124     /* */
 125     void                ( * pf_flush ) ( decoder_t * );
 126
 127     /* Closed Caption (CEA 608/708) extraction.
 128      * If set, it *may* be called after pf_packetize returned data. It should
 129      * return CC for the pictures returned by the last pf_packetize call only,
 130      * pb_present will be used to known which cc channel are present (but
 131      * globaly, not necessary for the current packet. Video decoders should use
 132      * the decoder_QueueCc() function to pass closed captions. */
 133     block_t *           ( * pf_get_cc )      ( decoder_t *, bool pb_present[4], int * );
 134
 135     /* Meta data at codec level
 136      *  The decoder owner set it back to NULL once it has retreived what it needs.
 137      *  The decoder owner is responsible of its release except when you overwrite it.
 138      */
 139     vlc_meta_t          *p_description;
 140
 141     /*
 142      * Owner fields
 143      * XXX You MUST not use them directly.
 144      */
 145
 146     /* Video output callbacks
 147      * XXX use decoder_NewPicture */
 148     int             (*pf_vout_format_update)( decoder_t * );
 149     picture_t      *(*pf_vout_buffer_new)( decoder_t * );
 150
 151     /**
 152      * Number of extra (ie in addition to the DPB) picture buffers
 153      * needed for decoding.
 154      */
 155     int             i_extra_picture_buffers;
 156
 157     /* Audio output callbacks */
 158     int             (*pf_aout_format_update)( decoder_t * );
 159
 160     /* SPU output callbacks
 161      * XXX use decoder_NewSubpicture */
 162     subpicture_t   *(*pf_spu_buffer_new)( decoder_t *, const subpicture_updater_t * );
 163
 164     /* Input attachments
 165      * XXX use decoder_GetInputAttachments */
 166     int             (*pf_get_attachments)( decoder_t *p_dec, input_attachment_t ***ppp_attachment, int *pi_attachment );
 167
 168     /* Display date
 169      * XXX use decoder_GetDisplayDate */
 170     mtime_t         (*pf_get_display_date)( decoder_t *, mtime_t );
 171
 172     /* Display rate
 173      * XXX use decoder_GetDisplayRate */
 174     int             (*pf_get_display_rate)( decoder_t * );
 175
 176     /* XXX use decoder_QueueVideo or decoder_QueueVideoWithCc */
 177     int             (*pf_queue_video)( decoder_t *, picture_t * );
 178     /* XXX use decoder_QueueAudio */
 179     int             (*pf_queue_audio)( decoder_t *, block_t * );
 180     /* XXX use decoder_QueueCC */
 181     int             (*pf_queue_cc)( decoder_t *, block_t *, bool p_cc_present[4], int );
 182     /* XXX use decoder_QueueSub */
 183     int             (*pf_queue_sub)( decoder_t *, subpicture_t *);
 184     void             *p_queue_ctx;
 185
 186     /* Private structure for the owner of the decoder */
 187     decoder_owner_sys_t *p_owner;
 188 };
 189
 190 /**
 191  * @}
 192  */
 193
 194 /**
 195  * \defgroup encoder Encoder
 196  * Audio, video and text encoders
 197  * @{
 198  */
 199
 200 struct encoder_t
 201 {
 202     VLC_COMMON_MEMBERS
 203
 204     /* Module properties */
 205     module_t *          p_module;
 206     encoder_sys_t *     p_sys;
 207
 208     /* Properties of the input data fed to the encoder */
 209     es_format_t         fmt_in;
 210
 211     /* Properties of the output of the encoder */
 212     es_format_t         fmt_out;
 213
 214     block_t *           ( * pf_encode_video )( encoder_t *, picture_t * );
 215     block_t *           ( * pf_encode_audio )( encoder_t *, block_t * );
 216     block_t *           ( * pf_encode_sub )( encoder_t *, subpicture_t * );
 217
 218     /* Common encoder options */
 219     int i_threads;               /* Number of threads to use during encoding */
 220     int i_iframes;               /* One I frame per i_iframes */
 221     int i_bframes;               /* One B frame per i_bframes */
 222     int i_tolerance;             /* Bitrate tolerance */
 223
 224     /* Encoder config */
 225     config_chain_t *p_cfg;
 226 };
 227
 228 /**
 229  * @}
 230  *
 231  * \ingroup decoder
 232  * @{
 233  */
 234
 235 /**
 236  * Updates the video output format.
 237  *
 238  * This function notifies the video output pipeline of a new video output
 239  * format (fmt_out.video). If there was no video output from the decoder so far
 240  * or if the video output format has changed, a new video output will be set
 241  * up. decoder_NewPicture() can then be used to allocate picture buffers.
 242  *
 243  * If the format is unchanged, this function has no effects and returns zero.
 244  *
 245  * \note
 246  * This function is not reentrant.
 247  *
 248  * @return 0 if the video output was set up successfully, -1 otherwise.
 249  */
 250 VLC_USED
 251 static inline int decoder_UpdateVideoFormat( decoder_t *dec )
 252 {
 253     assert( dec->fmt_in.i_cat == VIDEO_ES );
 254     if( dec->fmt_in.i_cat == VIDEO_ES && dec->pf_vout_format_update != NULL )
 255         return dec->pf_vout_format_update( dec );
 256     else
 257         return -1;
 258 }
 259
 260 /**
 261  * Allocates an output picture buffer.
 262  *
 263  * This function pulls an output picture buffer for the decoder from the
 264  * buffer pool of the video output. The picture must be released with
 265  * picture_Release() when it is no longer referenced by the decoder.
 266  *
 267  * \note
 268  * This function is reentrant. However, decoder_UpdateVideoFormat() cannot be
 269  * used concurrently; the caller is responsible for serialization.
 270  *
 271  * \warning
 272  * The behaviour is undefined if decoder_UpdateVideoFormat() was not called or
 273  * if the last call returned an error.
 274  *
 275  * \return a picture buffer on success, NULL on error
 276  */
 277 VLC_USED
 278 static inline picture_t *decoder_NewPicture( decoder_t *dec )
 279 {
 280     return dec->pf_vout_buffer_new( dec );
 281 }
 282
 283 /**
 284  * Abort any calls of decoder_NewPicture
 285  *
 286  * If b_abort is true, all pending and futures calls of decoder_NewPicture
 287  * will be aborted. This function can be used by asynchronous video decoders
 288  * to unblock a thread that is waiting for a picture.
 289  */
 290 VLC_API void decoder_AbortPictures( decoder_t *dec, bool b_abort );
 291
 292 /**
 293  * This function queues a single picture to the video output.
 294  *
 295  * \note
 296  * The caller doesn't own the picture anymore after this call (even in case of
 297  * error).
 298  * FIXME: input_DecoderFrameNext won't work if a module use this function.
 299  *
 300  * \return 0 if the picture is queued, -1 on error
 301  */
 302 static inline int decoder_QueueVideo( decoder_t *dec, picture_t *p_pic )
 303 {
 304     assert( p_pic->p_next == NULL );
 305     assert( dec->pf_queue_video != NULL );
 306     return dec->pf_queue_video( dec, p_pic );
 307 }
 308
 309 /**
 310  * This function queues the Closed Captions
 311  *
 312  * \param dec the decoder object
 313  * \param p_cc the closed-caption to queue
 314  * \param p_cc_present array-of-bool where each entry indicates whether the
 315  *                     given channel is present or not
 316  * \param i_depth the closed-caption to queue reorder depth, or simply 0
 317  *                     if using the old mpgv block flag tagging
 318  * \return 0 if queued, -1 on error
 319  */
 320 static inline int decoder_QueueCc( decoder_t *dec, block_t *p_cc,
 321                                    bool p_cc_present[4], int i_depth )
 322 {
 323     if( dec->pf_queue_cc == NULL )
 324     {
 325         block_Release( p_cc );
 326         return -1;
 327     }
 328     return dec->pf_queue_cc( dec, p_cc, p_cc_present, i_depth );
 329 }
 330
 331 /**
 332  * This function queues a single audio block to the audio output.
 333  *
 334  * \note
 335  * The caller doesn't own the audio block anymore after this call (even in case
 336  * of error).
 337  *
 338  * \return 0 if the block is queued, -1 on error
 339  */
 340 static inline int decoder_QueueAudio( decoder_t *dec, block_t *p_aout_buf )
 341 {
 342     assert( p_aout_buf->p_next == NULL );
 343     assert( dec->pf_queue_audio != NULL );
 344     return dec->pf_queue_audio( dec, p_aout_buf );
 345 }
 346
 347 /**
 348  * This function queues a single subtitle to the video output.
 349  *
 350  * \note
 351  * The caller doesn't own the subtitle anymore after this call (even in case of
 352  * error).
 353  *
 354  * \return 0 if the subtitle is queued, -1 on error
 355  */
 356 static inline int decoder_QueueSub( decoder_t *dec, subpicture_t *p_spu )
 357 {
 358     assert( p_spu->p_next == NULL );
 359     assert( dec->pf_queue_sub != NULL );
 360     return dec->pf_queue_sub( dec, p_spu );
 361 }
 362
 363 /**
 364  * This function notifies the audio output pipeline of a new audio output
 365  * format (fmt_out.audio). If there is currently no audio output or if the
 366  * audio output format has changed, a new audio output will be set up.
 367  * @return 0 if the audio output is working, -1 if not. */
 368 VLC_USED
 369 static inline int decoder_UpdateAudioFormat( decoder_t *dec )
 370 {
 371     assert(dec->fmt_in.i_cat == AUDIO_ES);
 372     if( dec->fmt_in.i_cat == AUDIO_ES && dec->pf_aout_format_update != NULL )
 373         return dec->pf_aout_format_update( dec );
 374     else
 375         return -1;
 376 }
 377
 378 /**
 379  * This function will return a new audio buffer usable by a decoder as an
 380  * output buffer. It must be released with block_Release() or returned it to
 381  * the caller as a decoder_QueueAudio parameter.
 382  */
 383 VLC_API block_t * decoder_NewAudioBuffer( decoder_t *, int i_nb_samples ) VLC_USED;
 384
 385 /**
 386  * This function will return a new subpicture usable by a decoder as an output
 387  * buffer. You have to release it using subpicture_Delete() or by returning
 388  * it to the caller as a decoder_QueueSub parameter.
 389  */
 390 VLC_API subpicture_t * decoder_NewSubpicture( decoder_t *, const subpicture_updater_t * ) VLC_USED;
 391
 392 /**
 393  * This function gives all input attachments at once.
 394  *
 395  * You MUST release the returned values
 396  */
 397 VLC_API int decoder_GetInputAttachments( decoder_t *, input_attachment_t ***ppp_attachment, int *pi_attachment );
 398
 399 /**
 400  * This function converts a decoder timestamp into a display date comparable
 401  * to mdate().
 402  * You MUST use it *only* for gathering statistics about speed.
 403  */
 404 VLC_API mtime_t decoder_GetDisplayDate( decoder_t *, mtime_t ) VLC_USED;
 405
 406 /**
 407  * This function returns the current input rate.
 408  * You MUST use it *only* for gathering statistics about speed.
 409  */
 410 VLC_API int decoder_GetDisplayRate( decoder_t * ) VLC_USED;
 411
 412 /** @} */
 413 /** @} */
 414 #endif /* _VLC_CODEC_H */